The invention relates to a vehicle having a bumper which runs transverse to the longitudinal direction of the vehicle and is attached to the vehicle by at least one deforming element that is essentially in the form of a tube-shaped length of section of light-weight metal having its longitudinal axis lying in the longitudinal direction of the vehicle.
A large number of devices for securing bumpers to a vehicle is known. It is also known to attach bumpers to vehicles via deforming elements on the longitudinal members of the vehicle frame, this in order to increase the capacity to absorb the energy of deformation entering the bumper during collision.
A known deforming element comprises an upset steel pipe which is attached to the bumper via attachment plates on the longitudinal member of the vehicle frame. This deforming element is characterized by practically uniform force of deformation throughout the deformation process. This desirable characteristic is obtained, however, only provided the direction of the force of deformation coincides with the longitudinal axis of the tube. Even when the deviation from that condition is only relatively small, the upsetting action does not take place and, instead, the tube is bent to the side without the desired absorption of energy. On collision with a soft obstacle, the pipe penetrates the obstacle and is not able therefore to exercise its full capacity for absorbing the incoming energy. A further disadvantage of the upset tube is its high cost of manufacture.
Efforts have already been made to employ hollow aluminum sections as deforming elements. However, relatively coarse folds forming during compression markedly reduce the capacity to absorb the incoming energy. Attempts have also been made to achieve better folding behavior by controlling the manner of folding; by this means however it has been possible to achieve only insignificant improvement.